As a part of the research on the explosion treatment of hazardous chemicals, explosion treatment tests have been attempted to evaluate quantitative decomposition ratio of the model compounds using small scale sealed container and primary explosive.It was found that the relationship between the decomposition ratio and product gases' compositions could be used for estimating the decomposition ratio of model compounds at explosion treatment when used silver azide as a primary explosive and naphthalene as a model compound. And this methods might be able to be applied for larger scale experiments as well.It is necessary to develop a standard experimental procedure for evaluating explosive decomposition behavior of chemicals, in order to find out the applicability of the exposion treatment method to various kinds of chemicals. Some experimental works has been done to determine the standard procedure. And the experimental conditions including experimental vessel size, amount of explosive, atmospheric gasses, sample/explosive ratio, contact condition between explosive and sample, and evaluation method for determining decomposition rate from gaseous products was determined as a standard.